/****************************************************************
 *
 * random.c: Contains the dSFMT, a prng
 *           adapted from Mutsuo Saito and Makoto Matsumoto
 *
 *****************************************************************
 *
 * Copyright 2002-2018 - the potfit development team
 *
 * https://www.potfit.net/
 *
 ****************************************************************
 *
 * This file is part of potfit.
 *
 * potfit is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * potfit is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with potfit; if not, see <http://www.gnu.org/licenses/>.
 *
 *****************************************************************/

/**
 * @file dSFMT.c
 * @brief double precision SIMD-oriented Fast Mersenne Twister (dSFMT)
 * based on IEEE 754 format.
 *
 * @author Mutsuo Saito (Hiroshima University)
 * @author Makoto Matsumoto (Hiroshima University)
 *
 * Copyright (C) 2007,2008 Mutsuo Saito, Makoto Matsumoto and Hiroshima
 * University. All rights reserved.
 *
 * The new BSD License is applied to this software, see LICENSE.txt
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "random_dsfmt.h"

/** dsfmt internal state vector */
dsfmt_t dsfmt_global_data;
/** dsfmt mexp for check */
static const int dsfmt_mexp = DSFMT_MEXP;

/*----------------
  STATIC FUNCTIONS
  ----------------*/
inline static uint32_t ini_func1(uint32_t x);
inline static uint32_t ini_func2(uint32_t x);
inline static void gen_rand_array_c1o2(dsfmt_t* dsfmt, w128_t* array, int size);
inline static void gen_rand_array_c0o1(dsfmt_t* dsfmt, w128_t* array, int size);
inline static void gen_rand_array_o0c1(dsfmt_t* dsfmt, w128_t* array, int size);
inline static void gen_rand_array_o0o1(dsfmt_t* dsfmt, w128_t* array, int size);
inline static int idxof(int i);
static void initial_mask(dsfmt_t* dsfmt);
static void period_certification(dsfmt_t* dsfmt);

#if defined(HAVE_SSE2)
#include <emmintrin.h>
/** mask data for sse2 */
static __m128i sse2_param_mask;
/** 1 in 64bit for sse2 */
static __m128i sse2_int_one;
/** 2.0 double for sse2 */
static __m128d sse2_double_two;
/** -1.0 double for sse2 */
static __m128d sse2_double_m_one;

static void setup_const(void);
#endif

/**
 * This function simulate a 32-bit array index overlapped to 64-bit
 * array of LITTLE ENDIAN in BIG ENDIAN machine.
 */
#if defined(DSFMT_BIG_ENDIAN)
inline static int idxof(int i) { return i ^ 1; }
#else
inline static int idxof(int i) { return i; }
#endif

/**
 * This function represents the recursion formula.
 * @param r output
 * @param a a 128-bit part of the internal state array
 * @param b a 128-bit part of the internal state array
 * @param lung a 128-bit part of the internal state array
 */
#if defined(HAVE_ALTIVEC)
inline static void do_recursion(w128_t* r, w128_t* a, w128_t* b, w128_t* lung)
{
  const vector unsigned char sl1 = ALTI_SL1;
  const vector unsigned char sl1_perm = ALTI_SL1_PERM;
  const vector unsigned int sl1_msk = ALTI_SL1_MSK;
  const vector unsigned char sr1 = ALTI_SR;
  const vector unsigned char sr1_perm = ALTI_SR_PERM;
  const vector unsigned int sr1_msk = ALTI_SR_MSK;
  const vector unsigned char perm = ALTI_PERM;
  const vector unsigned int msk1 = ALTI_MSK;
  vector unsigned int w, x, y, z;

  z = a->s;
  w = lung->s;
  x = vec_perm(w, (vector unsigned int)perm, perm);
  y = vec_perm(z, sl1_perm, sl1_perm);
  y = vec_sll(y, sl1);
  y = vec_and(y, sl1_msk);
  w = vec_xor(x, b->s);
  w = vec_xor(w, y);
  x = vec_perm(w, (vector unsigned int)sr1_perm, sr1_perm);
  x = vec_srl(x, sr1);
  x = vec_and(x, sr1_msk);
  y = vec_and(w, msk1);
  z = vec_xor(z, y);
  r->s = vec_xor(z, x);
  lung->s = w;
}
#elif defined(HAVE_SSE2)
/**
 * This function setup some constant variables for SSE2.
 */
static void setup_const(void)
{
  static int first = 1;
  if (!first) {
    return;
  }
  sse2_param_mask =
      _mm_set_epi32(DSFMT_MSK32_3, DSFMT_MSK32_4, DSFMT_MSK32_1, DSFMT_MSK32_2);
  sse2_int_one = _mm_set_epi32(0, 1, 0, 1);
  sse2_double_two = _mm_set_pd(2.0, 2.0);
  sse2_double_m_one = _mm_set_pd(-1.0, -1.0);
  first = 0;
}

/**
 * This function represents the recursion formula.
 * @param r output 128-bit
 * @param a a 128-bit part of the internal state array
 * @param b a 128-bit part of the internal state array
 * @param d a 128-bit part of the internal state array (I/O)
 */
inline static void do_recursion(w128_t* r, w128_t* a, w128_t* b, w128_t* u)
{
  __m128i v, w, x, y, z;

  x = a->si;
  z = _mm_slli_epi64(x, DSFMT_SL1);
  y = _mm_shuffle_epi32(u->si, SSE2_SHUFF);
  z = _mm_xor_si128(z, b->si);
  y = _mm_xor_si128(y, z);

  v = _mm_srli_epi64(y, DSFMT_SR);
  w = _mm_and_si128(y, sse2_param_mask);
  v = _mm_xor_si128(v, x);
  v = _mm_xor_si128(v, w);
  r->si = v;
  u->si = y;
}
#else /* standard C */
/**
 * This function represents the recursion formula.
 * @param r output 128-bit
 * @param a a 128-bit part of the internal state array
 * @param b a 128-bit part of the internal state array
 * @param lung a 128-bit part of the internal state array (I/O)
 */
inline static void do_recursion(w128_t* r, w128_t* a, w128_t* b, w128_t* lung)
{
  uint64_t t0, t1, L0, L1;

  t0 = a->u[0];
  t1 = a->u[1];
  L0 = lung->u[0];
  L1 = lung->u[1];
  lung->u[0] = (t0 << DSFMT_SL1) ^ (L1 >> 32) ^ (L1 << 32) ^ b->u[0];
  lung->u[1] = (t1 << DSFMT_SL1) ^ (L0 >> 32) ^ (L0 << 32) ^ b->u[1];
  r->u[0] = (lung->u[0] >> DSFMT_SR) ^ (lung->u[0] & DSFMT_MSK1) ^ t0;
  r->u[1] = (lung->u[1] >> DSFMT_SR) ^ (lung->u[1] & DSFMT_MSK2) ^ t1;
}
#endif

#if defined(HAVE_SSE2)
/**
 * This function converts the double precision floating point numbers which
 * distribute uniformly in the range [1, 2) to those which distribute uniformly
 * in the range [0, 1).
 * @param w 128bit stracture of double precision floating point numbers (I/O)
 */
inline static void convert_c0o1(w128_t* w)
{
  w->sd = _mm_add_pd(w->sd, sse2_double_m_one);
}

/**
 * This function converts the double precision floating point numbers which
 * distribute uniformly in the range [1, 2) to those which distribute uniformly
 * in the range (0, 1].
 * @param w 128bit stracture of double precision floating point numbers (I/O)
 */
inline static void convert_o0c1(w128_t* w)
{
  w->sd = _mm_sub_pd(sse2_double_two, w->sd);
}

/**
 * This function converts the double precision floating point numbers which
 * distribute uniformly in the range [1, 2) to those which distribute uniformly
 * in the range (0, 1).
 * @param w 128bit stracture of double precision floating point numbers (I/O)
 */
inline static void convert_o0o1(w128_t* w)
{
  w->si = _mm_or_si128(w->si, sse2_int_one);
  w->sd = _mm_add_pd(w->sd, sse2_double_m_one);
}
#else /* standard C and altivec */
/**
 * This function converts the double precision floating point numbers which
 * distribute uniformly in the range [1, 2) to those which distribute uniformly
 * in the range [0, 1).
 * @param w 128bit stracture of double precision floating point numbers (I/O)
 */
inline static void convert_c0o1(w128_t* w)
{
  w->d[0] -= 1.0;
  w->d[1] -= 1.0;
}

/**
 * This function converts the double precision floating point numbers which
 * distribute uniformly in the range [1, 2) to those which distribute uniformly
 * in the range (0, 1].
 * @param w 128bit stracture of double precision floating point numbers (I/O)
 */
inline static void convert_o0c1(w128_t* w)
{
  w->d[0] = 2.0 - w->d[0];
  w->d[1] = 2.0 - w->d[1];
}

/**
 * This function converts the double precision floating point numbers which
 * distribute uniformly in the range [1, 2) to those which distribute uniformly
 * in the range (0, 1).
 * @param w 128bit stracture of double precision floating point numbers (I/O)
 */
inline static void convert_o0o1(w128_t* w)
{
  w->u[0] |= 1;
  w->u[1] |= 1;
  w->d[0] -= 1.0;
  w->d[1] -= 1.0;
}
#endif

/**
 * This function fills the user-specified array with double precision
 * floating point pseudorandom numbers of the IEEE 754 format.
 * @param dsfmt dsfmt state vector.
 * @param array an 128-bit array to be filled by pseudorandom numbers.
 * @param size number of 128-bit pseudorandom numbers to be generated.
 */
inline static void gen_rand_array_c1o2(dsfmt_t* dsfmt, w128_t* array, int size)
{
  int i, j;
  w128_t lung;

  lung = dsfmt->status[DSFMT_N];
  do_recursion(&array[0], &dsfmt->status[0], &dsfmt->status[DSFMT_POS1], &lung);
  for (i = 1; i < DSFMT_N - DSFMT_POS1; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &dsfmt->status[i + DSFMT_POS1],
                 &lung);
  }
  for (; i < DSFMT_N; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &array[i + DSFMT_POS1 - DSFMT_N],
                 &lung);
  }
  for (; i < size - DSFMT_N; i++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
  }
  for (j = 0; j < 2 * DSFMT_N - size; j++) {
    dsfmt->status[j] = array[j + size - DSFMT_N];
  }
  for (; i < size; i++, j++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    dsfmt->status[j] = array[i];
  }
  dsfmt->status[DSFMT_N] = lung;
}

/**
 * This function fills the user-specified array with double precision
 * floating point pseudorandom numbers of the IEEE 754 format.
 * @param dsfmt dsfmt state vector.
 * @param array an 128-bit array to be filled by pseudorandom numbers.
 * @param size number of 128-bit pseudorandom numbers to be generated.
 */
inline static void gen_rand_array_c0o1(dsfmt_t* dsfmt, w128_t* array, int size)
{
  int i, j;
  w128_t lung;

  lung = dsfmt->status[DSFMT_N];
  do_recursion(&array[0], &dsfmt->status[0], &dsfmt->status[DSFMT_POS1], &lung);
  for (i = 1; i < DSFMT_N - DSFMT_POS1; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &dsfmt->status[i + DSFMT_POS1],
                 &lung);
  }
  for (; i < DSFMT_N; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &array[i + DSFMT_POS1 - DSFMT_N],
                 &lung);
  }
  for (; i < size - DSFMT_N; i++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    convert_c0o1(&array[i - DSFMT_N]);
  }
  for (j = 0; j < 2 * DSFMT_N - size; j++) {
    dsfmt->status[j] = array[j + size - DSFMT_N];
  }
  for (; i < size; i++, j++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    dsfmt->status[j] = array[i];
    convert_c0o1(&array[i - DSFMT_N]);
  }
  for (i = size - DSFMT_N; i < size; i++) {
    convert_c0o1(&array[i]);
  }
  dsfmt->status[DSFMT_N] = lung;
}

/**
 * This function fills the user-specified array with double precision
 * floating point pseudorandom numbers of the IEEE 754 format.
 * @param dsfmt dsfmt state vector.
 * @param array an 128-bit array to be filled by pseudorandom numbers.
 * @param size number of 128-bit pseudorandom numbers to be generated.
 */
inline static void gen_rand_array_o0o1(dsfmt_t* dsfmt, w128_t* array, int size)
{
  int i, j;
  w128_t lung;

  lung = dsfmt->status[DSFMT_N];
  do_recursion(&array[0], &dsfmt->status[0], &dsfmt->status[DSFMT_POS1], &lung);
  for (i = 1; i < DSFMT_N - DSFMT_POS1; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &dsfmt->status[i + DSFMT_POS1],
                 &lung);
  }
  for (; i < DSFMT_N; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &array[i + DSFMT_POS1 - DSFMT_N],
                 &lung);
  }
  for (; i < size - DSFMT_N; i++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    convert_o0o1(&array[i - DSFMT_N]);
  }
  for (j = 0; j < 2 * DSFMT_N - size; j++) {
    dsfmt->status[j] = array[j + size - DSFMT_N];
  }
  for (; i < size; i++, j++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    dsfmt->status[j] = array[i];
    convert_o0o1(&array[i - DSFMT_N]);
  }
  for (i = size - DSFMT_N; i < size; i++) {
    convert_o0o1(&array[i]);
  }
  dsfmt->status[DSFMT_N] = lung;
}

/**
 * This function fills the user-specified array with double precision
 * floating point pseudorandom numbers of the IEEE 754 format.
 * @param dsfmt dsfmt state vector.
 * @param array an 128-bit array to be filled by pseudorandom numbers.
 * @param size number of 128-bit pseudorandom numbers to be generated.
 */
inline static void gen_rand_array_o0c1(dsfmt_t* dsfmt, w128_t* array, int size)
{
  int i, j;
  w128_t lung;

  lung = dsfmt->status[DSFMT_N];
  do_recursion(&array[0], &dsfmt->status[0], &dsfmt->status[DSFMT_POS1], &lung);
  for (i = 1; i < DSFMT_N - DSFMT_POS1; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &dsfmt->status[i + DSFMT_POS1],
                 &lung);
  }
  for (; i < DSFMT_N; i++) {
    do_recursion(&array[i], &dsfmt->status[i], &array[i + DSFMT_POS1 - DSFMT_N],
                 &lung);
  }
  for (; i < size - DSFMT_N; i++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    convert_o0c1(&array[i - DSFMT_N]);
  }
  for (j = 0; j < 2 * DSFMT_N - size; j++) {
    dsfmt->status[j] = array[j + size - DSFMT_N];
  }
  for (; i < size; i++, j++) {
    do_recursion(&array[i], &array[i - DSFMT_N],
                 &array[i + DSFMT_POS1 - DSFMT_N], &lung);
    dsfmt->status[j] = array[i];
    convert_o0c1(&array[i - DSFMT_N]);
  }
  for (i = size - DSFMT_N; i < size; i++) {
    convert_o0c1(&array[i]);
  }
  dsfmt->status[DSFMT_N] = lung;
}

/**
 * This function represents a function used in the initialization
 * by init_by_array
 * @param x 32-bit integer
 * @return 32-bit integer
 */
static uint32_t ini_func1(uint32_t x)
{
  return (x ^ (x >> 27)) * (uint32_t)1664525UL;
}

/**
 * This function represents a function used in the initialization
 * by init_by_array
 * @param x 32-bit integer
 * @return 32-bit integer
 */
static uint32_t ini_func2(uint32_t x)
{
  return (x ^ (x >> 27)) * (uint32_t)1566083941UL;
}

/**
 * This function initializes the internal state array to fit the IEEE
 * 754 format.
 * @param dsfmt dsfmt state vector.
 */
static void initial_mask(dsfmt_t* dsfmt)
{
  int i;
  uint64_t* psfmt;

  psfmt = &dsfmt->status[0].u[0];
  for (i = 0; i < DSFMT_N * 2; i++) {
    psfmt[i] = (psfmt[i] & DSFMT_LOW_MASK) | DSFMT_HIGH_CONST;
  }
}

/**
 * This function certificate the period of 2^{SFMT_MEXP}-1.
 * @param dsfmt dsfmt state vector.
 */
static void period_certification(dsfmt_t* dsfmt)
{
  uint64_t pcv[2] = {DSFMT_PCV1, DSFMT_PCV2};
  uint64_t tmp[2];
  uint64_t inner;
  int i;
#if (DSFMT_PCV2 & 1) != 1
  int j;
  uint64_t work;
#endif

  tmp[0] = (dsfmt->status[DSFMT_N].u[0] ^ DSFMT_FIX1);
  tmp[1] = (dsfmt->status[DSFMT_N].u[1] ^ DSFMT_FIX2);

  inner = tmp[0] & pcv[0];
  inner ^= tmp[1] & pcv[1];
  for (i = 32; i > 0; i >>= 1) {
    inner ^= inner >> i;
  }
  inner &= 1;
  /* check OK */
  if (inner == 1) {
    return;
  }
/* check NG, and modification */
#if (DSFMT_PCV2 & 1) == 1
  dsfmt->status[DSFMT_N].u[1] ^= 1;
#else
  for (i = 1; i >= 0; i--) {
    work = 1;
    for (j = 0; j < 64; j++) {
      if ((work & pcv[i]) != 0) {
        dsfmt->status[DSFMT_N].u[i] ^= work;
        return;
      }
      work = work << 1;
    }
  }
#endif
  return;
}

/*----------------
  PUBLIC FUNCTIONS
  ----------------*/
/**
 * This function returns the identification string.  The string shows
 * the Mersenne exponent, and all parameters of this generator.
 * @return id string.
 */
const char* dsfmt_get_idstring(void) { return DSFMT_IDSTR; }
/**
 * This function returns the minimum size of array used for \b
 * fill_array functions.
 * @return minimum size of array used for fill_array functions.
 */
int dsfmt_get_min_array_size(void) { return DSFMT_N64; }
/**
 * This function fills the internal state array with double precision
 * floating point pseudorandom numbers of the IEEE 754 format.
 * @param dsfmt dsfmt state vector.
 */
void dsfmt_gen_rand_all(dsfmt_t* dsfmt)
{
  int i;
  w128_t lung;

  lung = dsfmt->status[DSFMT_N];
  do_recursion(&dsfmt->status[0], &dsfmt->status[0], &dsfmt->status[DSFMT_POS1],
               &lung);
  for (i = 1; i < DSFMT_N - DSFMT_POS1; i++) {
    do_recursion(&dsfmt->status[i], &dsfmt->status[i],
                 &dsfmt->status[i + DSFMT_POS1], &lung);
  }
  for (; i < DSFMT_N; i++) {
    do_recursion(&dsfmt->status[i], &dsfmt->status[i],
                 &dsfmt->status[i + DSFMT_POS1 - DSFMT_N], &lung);
  }
  dsfmt->status[DSFMT_N] = lung;
}

/**
 * This function generates double precision floating point
 * pseudorandom numbers which distribute in the range [1, 2) to the
 * specified array[] by one call. The number of pseudorandom numbers
 * is specified by the argument \b size, which must be at least (SFMT_MEXP
 * / 128) * 2 and a multiple of two.  The function
 * get_min_array_size() returns this minimum size.  The generation by
 * this function is much faster than the following fill_array_xxx functions.
 *
 * For initialization, init_gen_rand() or init_by_array() must be called
 * before the first call of this function. This function can not be
 * used after calling genrand_xxx functions, without initialization.
 *
 * @param dsfmt dsfmt state vector.
 * @param array an array where pseudorandom numbers are filled
 * by this function.  The pointer to the array must be "aligned"
 * (namely, must be a multiple of 16) in the SIMD version, since it
 * refers to the address of a 128-bit integer.  In the standard C
 * version, the pointer is arbitrary.
 *
 * @param size the number of 64-bit pseudorandom integers to be
 * generated.  size must be a multiple of 2, and greater than or equal
 * to (SFMT_MEXP / 128) * 2.
 *
 * @note \b memalign or \b posix_memalign is available to get aligned
 * memory. Mac OSX doesn't have these functions, but \b malloc of OSX
 * returns the pointer to the aligned memory block.
 */
void dsfmt_fill_array_close1_open2(dsfmt_t* dsfmt, double array[], int size)
{
  assert(size % 2 == 0);
  assert(size >= DSFMT_N64);
  gen_rand_array_c1o2(dsfmt, (w128_t*)array, size / 2);
}

/**
 * This function generates double precision floating point
 * pseudorandom numbers which distribute in the range (0, 1] to the
 * specified array[] by one call. This function is the same as
 * fill_array_close1_open2() except the distribution range.
 *
 * @param dsfmt dsfmt state vector.
 * @param array an array where pseudorandom numbers are filled
 * by this function.
 * @param size the number of pseudorandom numbers to be generated.
 * see also \sa fill_array_close1_open2()
 */
void dsfmt_fill_array_open_close(dsfmt_t* dsfmt, double array[], int size)
{
  assert(size % 2 == 0);
  assert(size >= DSFMT_N64);
  gen_rand_array_o0c1(dsfmt, (w128_t*)array, size / 2);
}

/**
 * This function generates double precision floating point
 * pseudorandom numbers which distribute in the range [0, 1) to the
 * specified array[] by one call. This function is the same as
 * fill_array_close1_open2() except the distribution range.
 *
 * @param array an array where pseudorandom numbers are filled
 * by this function.
 * @param dsfmt dsfmt state vector.
 * @param size the number of pseudorandom numbers to be generated.
 * see also \sa fill_array_close1_open2()
 */
void dsfmt_fill_array_close_open(dsfmt_t* dsfmt, double array[], int size)
{
  assert(size % 2 == 0);
  assert(size >= DSFMT_N64);
  gen_rand_array_c0o1(dsfmt, (w128_t*)array, size / 2);
}

/**
 * This function generates double precision floating point
 * pseudorandom numbers which distribute in the range (0, 1) to the
 * specified array[] by one call. This function is the same as
 * fill_array_close1_open2() except the distribution range.
 *
 * @param dsfmt dsfmt state vector.
 * @param array an array where pseudorandom numbers are filled
 * by this function.
 * @param size the number of pseudorandom numbers to be generated.
 * see also \sa fill_array_close1_open2()
 */
void dsfmt_fill_array_open_open(dsfmt_t* dsfmt, double array[], int size)
{
  assert(size % 2 == 0);
  assert(size >= DSFMT_N64);
  gen_rand_array_o0o1(dsfmt, (w128_t*)array, size / 2);
}

#if defined(__INTEL_COMPILER)
#pragma warning(disable : 981)
#endif
/**
 * This function initializes the internal state array with a 32-bit
 * integer seed.
 * @param dsfmt dsfmt state vector.
 * @param seed a 32-bit integer used as the seed.
 * @param mexp caller's mersenne expornent
 */
void dsfmt_chk_init_gen_rand(dsfmt_t* dsfmt, uint32_t seed, int mexp)
{
  int i;
  uint32_t* psfmt;

  /* make sure caller program is compiled with the same MEXP */
  if (mexp != dsfmt_mexp) {
    fprintf(stderr, "DSFMT_MEXP doesn't match with dSFMT.c\n");
    exit(EXIT_FAILURE);
  }
  psfmt = &dsfmt->status[0].u32[0];
  psfmt[idxof(0)] = seed;
  for (i = 1; i < (DSFMT_N + 1) * 4; i++) {
    psfmt[idxof(i)] =
        1812433253UL * (psfmt[idxof(i - 1)] ^ (psfmt[idxof(i - 1)] >> 30)) + i;
  }
  initial_mask(dsfmt);
  period_certification(dsfmt);
  dsfmt->idx = DSFMT_N64;
#if defined(HAVE_SSE2)
  setup_const();
#endif
}

/**
 * This function initializes the internal state array,
 * with an array of 32-bit integers used as the seeds
 * @param dsfmt dsfmt state vector.
 * @param init_key the array of 32-bit integers, used as a seed.
 * @param key_length the length of init_key.
 * @param mexp caller's mersenne expornent
 */
void dsfmt_chk_init_by_array(dsfmt_t* dsfmt, uint32_t init_key[],
                             int key_length, int mexp)
{
  int i, j, count;
  uint32_t r;
  uint32_t* psfmt32;
  int lag;
  int mid;
  int size = (DSFMT_N + 1) * 4; /* pulmonary */

  /* make sure caller program is compiled with the same MEXP */
  if (mexp != dsfmt_mexp) {
    fprintf(stderr, "DSFMT_MEXP doesn't match with dSFMT.c\n");
    exit(EXIT_FAILURE);
  }
  if (size >= 623) {
    lag = 11;
  } else if (size >= 68) {
    lag = 7;
  } else if (size >= 39) {
    lag = 5;
  } else {
    lag = 3;
  }
  mid = (size - lag) / 2;

  psfmt32 = &dsfmt->status[0].u32[0];
  memset(dsfmt->status, 0x8b, sizeof(dsfmt->status));
  if (key_length + 1 > size) {
    count = key_length + 1;
  } else {
    count = size;
  }
  r = ini_func1(psfmt32[idxof(0)] ^ psfmt32[idxof(mid % size)] ^
                psfmt32[idxof((size - 1) % size)]);
  psfmt32[idxof(mid % size)] += r;
  r += key_length;
  psfmt32[idxof((mid + lag) % size)] += r;
  psfmt32[idxof(0)] = r;
  count--;
  for (i = 1, j = 0; (j < count) && (j < key_length); j++) {
    r = ini_func1(psfmt32[idxof(i)] ^ psfmt32[idxof((i + mid) % size)] ^
                  psfmt32[idxof((i + size - 1) % size)]);
    psfmt32[idxof((i + mid) % size)] += r;
    r += init_key[j] + i;
    psfmt32[idxof((i + mid + lag) % size)] += r;
    psfmt32[idxof(i)] = r;
    i = (i + 1) % size;
  }
  for (; j < count; j++) {
    r = ini_func1(psfmt32[idxof(i)] ^ psfmt32[idxof((i + mid) % size)] ^
                  psfmt32[idxof((i + size - 1) % size)]);
    psfmt32[idxof((i + mid) % size)] += r;
    r += i;
    psfmt32[idxof((i + mid + lag) % size)] += r;
    psfmt32[idxof(i)] = r;
    i = (i + 1) % size;
  }
  for (j = 0; j < size; j++) {
    r = ini_func2(psfmt32[idxof(i)] + psfmt32[idxof((i + mid) % size)] +
                  psfmt32[idxof((i + size - 1) % size)]);
    psfmt32[idxof((i + mid) % size)] ^= r;
    r -= i;
    psfmt32[idxof((i + mid + lag) % size)] ^= r;
    psfmt32[idxof(i)] = r;
    i = (i + 1) % size;
  }
  initial_mask(dsfmt);
  period_certification(dsfmt);
  dsfmt->idx = DSFMT_N64;
#if defined(HAVE_SSE2)
  setup_const();
#endif
}

#if defined(__INTEL_COMPILER)
#pragma warning(default : 981)
#endif
